Day trading isn't as simple as just buying low and selling high, it just doesn't work much with altcoins in my experience you got to do it in BTC/USDT. If you take a look at the SNTR today, its almost worthless coin where you can't even see updates that can make the coin spike a bit to attract traders but with BTC the price can just swing in everyday where your chances of earning is much larger.
Currently the price of SNTR is $ 0.000001, the value is very cheap, why does the OP keep SNTR coins for so long when this coin has no potential, only 2 exchanges have SNTR volume.
I agree with you that it's better to trade daily with BTC / USD or BTC / ETH with great opportunities and you can play with your strategy.